scholarly journals Enhanced Solar Light Photocatalytic Activity of Ag Doped TiO2–Ag3PO4 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 795 ◽  
Author(s):  
Abdessalem Hamrouni ◽  
Hanen Azzouzi ◽  
Ali Rayes ◽  
Leonardo Palmisano ◽  
Riccardo Ceccato ◽  
...  

Composites comprised of Ag3PO4 and bare TiO2 (TiO2@Ag3PO4) or silver doped TiO2 (Ag@TiO2–Ag3PO4) have been synthesized by coupling sol–gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis. The optoelectronic and structural features of the samples have been related to their photocatalytic activity for the degradation of 4–nitrophenol under solar and UV light irradiation. Coupling Ag3PO4 with silver doped TiO2 mitigates photocorrosion of the Ag3PO4 counterpart, and remarkably improves the photocatalytic activity under solar light irradiation with respect to the components, to the TiO2–Ag3PO4 sample, and to the benchmark TiO2 Evonik P25. These features open the route to future applications of this material in the field of environmental remediation.

2020 ◽  
Vol 9 (4) ◽  
pp. 42-48
Author(s):  
Nui Pham Xuan ◽  
Hoa Nguyen Thi ◽  
Tien Nguyen Trung ◽  
Tai Le Huu ◽  
Thi Tran Thi Van

In this research, photocatalytic materials of TiO2, Ag-TiO2, Ag-TiO2/perlite were synthesized by the sol-gel method. By combining the photocatalytic activity between Ag-TiO2 and Perlite mineral, the Ag-TiO2/perlite composite has overcome the disadvantages of pristine TiO2, such as high band gap energy, low light utilization and easy recombination of electrons and holes. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm, UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of the samples was tested for degradation of methylene blue (MB) under solar light irradiation. Photodegradation studies revealed a 95% removal of MB dye via the synthesized Ag-TiO2/perlite after 150 min of irradiation. Reusability of this hybrid photocatalyst system was tested and only a 3% decrease was observed after four cycles.


2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.


2015 ◽  
Vol 3 (34) ◽  
pp. 17858-17865 ◽  
Author(s):  
Xiaohong Hu ◽  
Qi Zhu ◽  
Xinlong Wang ◽  
Naoki Kawazoe ◽  
Yingnan Yang

P/Ag/Ag2O/Ag3PO4/TiO2 composite photocatalyst has been successfully prepared by a sol–gel method. It shows highly enhanced photocatalytic ability and stability under simulated solar light irradiation.


2019 ◽  
Vol 3 (3) ◽  
pp. 75 ◽  
Author(s):  
Mamo Gebrezgiabher ◽  
Gebrehiwot Gebreslassie ◽  
Tesfay Gebretsadik ◽  
Gebretinsae Yeabyo ◽  
Fikre Elemo ◽  
...  

Magnetically recyclable C-doped TiO2/Fe3O4 (C-TiO2/Fe3O4) nanocomposite was successfully synthesized via a sol–gel method. The synthesized samples were characterized using SEM, energy-dispersive X-ray spectroscopy (EDS), FTIR, and UV-VIS diffuse reflectance spectroscopy (DRS) techniques. The results clearly showed that a C-TiO2/Fe3O4 nanocomposite was produced. The photocatalytic activities of the prepared pristine (TiO2), C-doped TiO2 (C-TiO2) and C-TiO2/Fe3O4 were evaluated by the photodegradation of methyl orange (MO) under natural sunlight. The effect of catalyst loading and MO concentration were studied and optimized. The C-TiO2/Fe3O4 nanocomposite exhibited an excellent photocatalytic activity (99.68%) that was higher than the TiO2 (55.41%) and C-TiO2 (70%) photocatalysts within 150 min. The magnetic nanocomposite could be easily recovered from the treated solution by applying external magnetic field. The C-TiO2/Fe3O4 composite showed excellent photocatalytic performance for four consecutive photocatalytic reactions. Thus, this work could provide a simple method for the mass production of highly photoactive and stable C-TiO2/Fe3O4 photocatalyst for environmental remediation.


2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.


2010 ◽  
Vol 113-116 ◽  
pp. 1945-1950 ◽  
Author(s):  
Jie Luo ◽  
Xin Yuan Yang ◽  
De Liang Li

Using cesium nitrate and strontium nitrate as doping metal ions source, Cs-doped TiO2 and Sr-doped TiO2 photocatalysts were successfully synthesized through the hydrolysis of tetrabutyl titanate by an acid-catalyzed sol-gel method. The photocatalytic activities of these catalysts prepared at 600 °C for 2 h were evaluated by the degradation of methyl orange in aqueous solution under solar light irradiation, and the as-prepared samples with higher photocatalytic efficiency were characterized by means of X-ray diffraction (XRD) and UV-Vis absorption spectroscopy. The XRD patterns indicate that the crystal structure still remains as anatase phase for the doped samples, and the average crystal size of TiO2, 0.1 at% Cs-doped TiO2 and 0.3 at% Sr-doped TiO2 is 21.3, 13.1 and 10.8 nm, respectively. The band gap absorption shows red shift to the visible region for the doped samples from the UV-Vis spectrogram. The results show that the photocatalytic activity of TiO2 nanoparticles doped with Cs+ and Sr2+ exhibits a significant improvement and their degradation efficiencies are more than 30% in comparison with those of TiO2 under the same condition, and the optimal doping concentration is determined to be 0.1 at% and 0.3 at% for Cs+ and Sr2+, respectively.


2011 ◽  
Vol 391-392 ◽  
pp. 219-224
Author(s):  
Jin Huan Li ◽  
Hong Bo Fang ◽  
Wei Wang ◽  
Gui Fan Liu ◽  
Shao Dong Zhang

Nanocrystals with different Eu3+ doping levels (%) were prepared by sol-gel and hydrothermal synthetic method using titanium tetraisopropoxide (TTIP) as titanium source. The products exhibited anatase phase structure, mesoporosity, and interesting surface compositions with three oxygen species and two titanium species. The crystallite sizes, crystal form, surface shape, composition and optical property of catalysts were characterized by X-ray diffraction patterns, UV-Vis diffuse reflectance spectroscopy, XPS and inductively coupled plasma atomic emission spectroscopy. The products were used as the photocatalysts to degrade a partially hydrolysis polyacrylamide (HPAM) under UV-light irradiation, a very useful polymer in oil recovery. For comparison, Degussa P25 and as-prepared pure TiO2 were also tested under the same conditions. The enhanced photocatalytic activity was obtained on as-prepared Eu3+ composites, and the reasons were explained.


2020 ◽  
Vol 18 (6) ◽  
pp. 390-409
Author(s):  
S. P. Ramírez ◽  
J. A. Wang ◽  
M. A. Valenzuela ◽  
L. F. Chen ◽  
A. Dalai

Hydrogen production from the photocatalytic reforming of glycerol aqueous solution was performed on the CuO@TiO2, NiO@TiO2, NiO@CuO, and CuO@NiO core-shell nanostructured catalysts under simulated solar light irradiation. These catalysts were prepared by the combination of a modified sol-gel and a precipitation-deposition method using hydroxypropyl cellulose as structural linker and they were characterized by powder X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen physisorption isotherms techniques. The catalysts containing TiO2 as a shell and CuO as core showed much higher activity compared with those formulated with NiO@CuO, CuO@NiO, and bared CuO or NiO nanoparticles. The highest rate of hydrogen production obtained with the CuO@TiO2 catalyst was as high as 153.8 μmol·g−1h-1, which was 29.0, 24.8, 11.2 and 3.2 times greater than that obtained on CuO@NiO, NiO@CuO, TiO2 P25, and NiO@TiO2 catalyst, respectively. For the high active CuO@TiO2 catalyst, after activation of TiO2 with solar light irradiation, the conduction band electrons can be transferred to CuO core through the heterojunction in the core-shell interfaces which led to CuO gradually reduced to Cu2O, favoring the reduction of proton to release hydrogen.


2015 ◽  
Vol 1123 ◽  
pp. 227-232 ◽  
Author(s):  
Iqriah Kalim Susanto ◽  
Ardiansyah Taufik ◽  
Rosari Saleh

Nanocomposite Fe3O4-CuO-ZnO with different molar ratio of Fe3O4:CuO:ZnO were synthesized using sol-gel method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscope, UV-visible diffuse reflectance spectroscopy and vibrating sample magnetometer. The characterization results manifested that the combination of Fe3O4, CuO and ZnO nanoparticles was successful. The photocatalytic activity of nanocomposite with the molar ratio of 1:1:5 was more effective in the degradation of methylene blue under UV light irradiation than pure Fe3O4, CuO, ZnO. The role of photoactive species involved in the photocatalytic reaction was studied and found that holes play the most important role in photodegradation of methylene blue.


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